Kerberos: A wonder for network security, but a pain to install.
Many applications wish they had Kerberos support, but have not taken the time to implement it, mostly by lack of a Kerberos server to perform the tests.
So I created a ready-to-use Kerberos server VM!
Feel free to use it: Download the VM, start it in VirtualBox, and you have a working Kerberos server to test your applications!
The VM is 450MB, based on Turnkey Linux Domain Controller and Kerberos installed via this excellent guide. Accounts are described on the Kerberos VM SourceForge page.